1. Field of the Invention
Embodiments of the present invention relate to an automated single-stream material recovery facility (SSMRF). In particular, embodiments of the present invention relate to systems and methods for improving the flow of a recyclable product stream in a SSMRF.
2. Background Description
Waste management companies provide residential, commercial, and municipal waste management and recycling services for communities and organizations. Consumers include, for example, residential, industrial, and business customers. A waste management service provider may be utilized by municipalities to handle their municipal solid waste (MSW) and/or to provide recycling services for the municipalities.
MSW is refuse and recyclable materials that result, for example, from residential, commercial, industrial, and community activities. Often, municipalities require or encourage recycling selected materials such as plastic, aluminum, paper, cardboard, and glass. Generally, these materials are picked up by either a waste management company or a municipality and may be taken to an SSMRF, where mixed recyclable materials are separated. Once separated, materials may be segregated into various qualities and categories, depending upon SSMRF configuration. For example, clear glass may be removed from colored glass, certain grades of paper may be separated from cardboard, and plastic may be separated by type and color. Materials such as plastic, aluminum, paper and cardboard may then be compressed into bales using standard equipment and procedures.
Recyclable materials entering a SSMRF can include a mixture of recyclable items such as glass, plastics, and/or metal containers (collectively referred to herein as commingled containers), old newsprint (ONP), old corrugated containers (OCCs), and/or office paper (collectively referred to herein as fiber material). Within a SSMRF, various conveying systems can be used to transport recyclable item streams to various sorting stations where the recyclable items are sorted, either manually and/or by use of certain equipment. A stream of recyclable items entering a SSMRF can subsequently be separated into multiple streams for sorting. For example, an original stream of recyclable items can be separated into a stream of fiber material items and a stream of commingled containers. Then, for example, workers at a fiber sorting station or automated separating equipment can remove office paper items from the stream of fiber items, while a glass sorting station can remove glass containers from the stream of commingled containers.
However, because the relative percentage of various types of recyclable items in the original stream can vary, some sorting stations can experience a “pile-up” or backlog of items they need to process, while other sorting stations become idle or under-utilized. For example, when the original stream of recyclable items includes predominantly fiber items, a fiber sorting station may experience a backlog while a glass sorting station may be idle or substantially underutilized. This decreases the overall throughput of the SSMRF relative to a situation in which the fiber sorting station and the glass sorting station are both processing their respective fiber and glass items at or near capacity. In addition, the quality of fiber generated from the sorting stations during a period of backlog or pile-up can be adversely affected.
We have discovered that systems and methods for adjusting the speeds (and/or other operational aspects) of one or more conveyance systems in a SSMRF to purposefully regulate material flow can be utilized to provide improved operational efficiencies, realize higher throughput, and increase the quality of sorted recyclable material produced by the SSMRF. Embodiments of the present invention are directed to these and other objectives.